Gas turbine engines require fuel injection systems for delivering fuel to a combustion chamber in which the fuel is atomized and mixed with air before combustion. A fuel injection system may include one or more fuel spray nozzles to atomize the fuel in order to ensure its rapid evaporation and burning when mixed with air in the combustion chamber. A fuel spray nozzle may include a fuel injector which includes an annular fuel passage to deliver fuel and create an annular film of liquid fuel to be discharged from the annular fuel passage. The discharged annular liquid fuel film is then entrained in and atomized by swirling air streams produced by air swirlers. The swirling air streams move much more rapidly than the discharged liquid fuel film in order to atomize the latter. Efforts have been made to provide new configurations of fuel injectors and to improve fuel/air mixing and fuel atomization in order to achieve lean burn combustion while maintaining combustion efficiency during engine operation.
Accordingly there is a need for an improved fuel injector for a fuel spray nozzle and an improved method for spraying fuel into the combustor of gas turbine engines.